Method of checking waterproof connectors for waterproofness, and waterproofness checking apparatus and jig

ABSTRACT

A waterproof connector is checked for waterproofness, which waterproof connector has a terminal-accommodating chamber into which a terminal is inserted and which is sealed with a waterproofing rubber stopper through which an insulated wire attached to the terminal passes. A connector-holding block of a waterproofness-checking jig engages in a watertight manner with the connector-fitting side of the waterproof connector, followed by depressurizing the waterproof connector with an ejector and comparing the pressure inside the waterproof connector with a reference pressure to determine the presence or non-presence of a leakage. Owing to the depressurization of the waterproof connector, the terminal, if inserted incomplete, is moved into a fully-inserted position in the connector housing in one piece with the waterproofing rubber stopper. A waterproof connector can be easily and reliably checked for waterproofness without making errors, while remedying incomplete insertion of a terminal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method, apparatus and jig for checking thewaterproofness of a waterproof connector, by which a waterproofconnector--which is used for the mutual connection of wiring harnessesand the like--can be checked for waterproofness, while at the same timeincomplete insertion of a terminal into the connector is prevented.

2. Description of the Related Art

A waterproof connector generally has a construction as shown in FIG. 8.In other words, a waterproof connector A has a synthetic resin-madehousing body 1 in which a plurality of divided terminal-accommodatingchambers (terminal-accommodating holes) are formed- A metallic femaleterminal 3 is inserted into each accommodating chamber from the rear tobe locked therein. The female terminal 3 is crimped on and attached tothe end of an insulated wire 4 together with a waterproofing rubberstopper 5. The outer periphery of the rubber stopper 5 elasticallycontacts the inner wall of a related accommodating chamber 2 to providea waterproof seal. The housing body 1 is around its outer peripheryprovided with a waterproofing hood 6 and is fitted through a rubberpacking with a mating connector (not shown).

The waterproofness of the waterproof connector A will be adverselyaffected if the rubber stopper 5 is not present, improperly set orfaulty, or if the connector housing itself (housing body 1,waterproofing hood 6) is faulty.

Referring to FIG. 9, which is a block diagram of a conventional systemfor waterproofness checking, a pressure source 11 comprised of acompressor or compressed air is branched through a regulator 12 to beconnected to a waterproofness checking jig 13 and to a pressure sensor14. To the pressure sensor 14 a display 15 is connected as an outputdevice. Designated at 18 is an air pipeway.

To check for waterproofness, the waterproof connector A is set on thewaterproofness-checking jig 13 in a watertight manner, followed byapplying through the regulator 12 a predetermined pressure (positivepressure). The level of pressure inside the connector A is read (judged)by the pressure sensor 14, and its result is displayed on the display15, while at the same time compared with a reference pressure stored inadvance to output its result, for example, as a buzzer (alarm).

There are, however, various drawbacks to the conventional method inwhich pressurized air is supplied to the waterproof connector A. First,since the pressure inside the connector is susceptible to a change intemperature and the like, even if the seal between the rubber stopper 5and the related terminal-accommodating chamber 2 and between the rubberstopper 5 and the insulator of the insulated wire 4 is complete, thepressure inside the connector turns positive or negative as comparedwith the atmospheric pressure, making it difficult to accurately check.Second, since the waterproof connector is applied with a positivepressure, if the setting of the connector A on the checking jig 13 orthe insertion of the rubber stopper 5 is incomplete, there is a fearthat these elements will pop out. Third, much skill is required inquickly setting the waterproof connector in a watertight manner on thechecking jig, and in case such poping-out as mentioned above takesplace, it is necessary to reset what has popped out. As a result, muchtime is required as a whole before completion of the checking.

FIG. 10 shows a method according to which the above-referencedwaterproof connector A is checked for continuity, which method isdisclosed in Japanese Utility Model Application Laid-Open SpecificationNo. Sho 64-27668. In this method, continuity is checked as follows. Aspring-urged conductive pin (proving pin) 81 is at the front end pressedagainst the front end of the terminal 3 in the waterproof connector Aand at the rear end contacted with an electrode 82, while a lead wire 83with a lamp 84 is connected between the terminal 3 and the electrode 82so that the continuity is checked by the lighting of the lamp 84. Inthis instance, if the terminal 3 is in an incompletely inserted positionin the waterproof connector A, i.e., if a resilient locking lance 85 ofthe housing 1 is not engaged in the engagement hole (not shown) of theterminal 3, as the waterproof connector A is moved in the direction ofthe conductive pin 81, the terminal 3 is pushed to the outside so thatits incomplete insertion will be detected.

There is, however, a drawback to this method of checking for continuitythat, in the case where the engagement hole of the terminal 3 stops justin front of the locking lance 85, i.e., just before engagement, andwhere the terminal 3 is hard to move due to crooking of the insulatedwire 4 in a lateral direction or the like, the terminal 3 is not pushedout even when pressed by the conductive pin 81, resulting innon-detectability of an incompletely-inserted terminal.

SUMMARY OF THE INVENTION

This invention has been accomplished to overcome the above drawbacks andan object of this invention is to provide a method of checking thewaterproofness of a waterproof connector, by which method such checkingcan be reliably, safely and quickly done, while at the same timeincomplete insertion of a terminal in the waterproof connector can beprevented, and an apparatus and jig therefor.

In order to attain the object, according to an aspect of this invention,there is provided a method of checking a waterproof connector forwaterproofness comprising a connector housing with aterminal-accommodating chamber formed therein into which a terminalattached to an end of an insulated wire has been inserted from a firstside of the connector housing, the terminal-accommodating chamber havingbeen sealed by a waterproofing rubber stopper through which theinsulated wire passes, the method comprising the steps of: engaging aconnector-holding block in a watertight manner with a second side of theconnector housing at which the connector is fitted with a matingconnector; depressurizing an interior of the connector through theconnector-holding block; and detecting and comparing a pressure insidethe connector with a reference pressure preset to determine presence ornon-presence of leakage.

In the above method, since the waterproof connector is depressurizedthrough the connector-holding block, unlike the conventional method inwhich the connector is pressurized, there is no fear that thewaterproofing rubber stopper may pop out. Rather, the waterproofingrubber stopper, if inserted incomplete, is attracted under reducedpressure to a fully-inserted position in the connector housing. As aresult, it becomes possible to quickly determine the waterproofness ofthe connector.

According to another aspect of this invention, there is provided anapparatus for checking a waterproof connector for waterproofness,comprising: a waterproofness checking jig provided with aconnector-holding block for engaging and holding in a watertight mannera fitting side of the connector with a mating connector; means fordepressurizing an interior of the connector through theconnector-holding block and means for holding the interior of theconnector in the depressurized state; means for detecting a pressureinside the connector a certain period of time after commencement ofholding in the depressurized state and comparing the same with areference pressure preset to determine presence or non-presence ofleakage; and means for displaying the detected pressure inside theconnector and the presence or non-presence of leakage.

In the above apparatus which is for carrying out the checking method asdescribed above, since the connector-holding block engages and holds ina watertight manner the fitting side of the connector with a matingconnector, the setting of the connector for waterproofness checking canbe easily and reliably conducted. Owing to this as well as to thedetermining means and the displaying means which enable quick judgementof the waterproofness of the connector, the checking can be done rapidlyas a whole.

According to a further aspect of this invention, there is provided awaterproofness checking jig for holding a waterproof connectorcomprising a connector housing with a terminal-accommodating chamberformed therein into which a terminal attached to an end of an insulatedwire has been inserted from a first side of the connector housing, theterminal-accommodating chamber having been sealed by a waterproofingrubber stopper through which the insulated wire passes, thewaterproofing checking jig comprising: a framing; a sub-holding blockprovided at one end of the framing for supporting the first side of theconnector; a connector-holding block provided slidable between thesub-holding block and the other end of the framing for engaging andholding in a watertight manner a second side of the connector at whichthe connector is fitted with a mating connector; an air pipewayconnected to the connector-holding block for depressurizing andpressurizing the connector through the connector-holding block; and arotatable lever provided with a toggle mechanism for moving theconnector-holding block forwardly and backwardly between the sub-holdingblock and the other end of the framing.

In the checking jig of the above construction, if the lever is rotatedwith the terminal-insertion side of the connector supported on thesub-holding block, the connector-holding block engages in a watertightmanner with the connector-fitting side of the connector through thetoggle mechanism, making it possible for an inexperienced worker to setthe connector easily, quickly and reliably and perform the checking withfew errors.

According to yet a further aspect of this invention, there is provided amethod of checking a waterproof connector for waterproofness comprisinga connector housing with a terminal-accommodating chamber formed thereininto which a terminal attached to an end of an insulated wire has beeninserted from a first side of the connector housing, theterminal-accommodating chamber having been sealed by a waterproofingrubber stopper through which the insulated wire passes, the methodcomprising the steps of: engaging a connector-holding block in awatertight manner with a second side of the connector housing at whichthe connector is fitted with a mating connector; and depressurizing aninterior of the connector through the connector-holding block, whereinduring the depressurization of the interior of the connector, theterminal, if inserted incomplete, is sucked in one piece with thewaterproofing rubber stopper into a fully-inserted position.

According to yet a further aspect of this invention, there is providedan apparatus for checking a waterproof connector for waterproofnesscomprising a connector housing with a terminal-accommodating chamberformed therein into which a terminal attached to an end of an insulatedwire has been inserted from a first side of the connector housing, theterminal-accommodating chamber having been sealed by a waterproofingrubber stopper through which the insulated wire passes, the apparatuscomprising: a waterproofness checking jig having a connector-holdingblock for engaging in a watertight manner with a second side of theconnector at which the connector is fitted with a mating connector; andmeans for depressurizing an interior of the connector through theconnector-holding block and means for holding the interior of theconnector in the depressurized state, wherein during depressurization ofthe interior of the connector, the terminal, if inserted incomplete, issucked in one piece with the waterproofing rubber stopper into afully-inserted position.

In the above method as well as in the above apparatus, owing to thedepressurization of the waterproof connector for checking forwaterproofness, the terminal, if inserted incomplete, is attracted inthe terminal-insertion direction and moved in one piece with thewaterproofing rubber stopper into a fully-inserted position.Consequently, the incomplete insertion of the terminal is remedied.

The above and other objects, features and advantages of this inventionwill become apparent from the following description and the appendedclaims, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system block diagram for explaining a method of checking aconnector for waterproofness according to this invention;

FIG. 2 is a perspective view of a waterproofness checking apparatusaccording to one embodiment of this invention;

FIG. 3 is a perspective view of a waterproofness checking jig used inthe apparatus of FIG. 2;

FIG. 4 is a side view of the waterproofness checking jig of FIG. 3;

FIG. 5 is a longitudinal sectional view of the waterproofness checkingapparatus;

FIG. 6 is a longitudinal sectional view of an essential portion of FIG.5, in the state where the waterproof connector is held in a watertightmanner;

FIG. 7 is a longitudinal sectional view of an essential portion of FIG.5, in the state where the inside of the waterproof connector isdepressurized;

FIG. 8 is an explanatory view of a conventional waterproof connector;

FIG. 9 is a system block diagram for explaining a conventional methodfor checking a connector for waterproofness; and

FIG. 10 is a longitudinal sectional view showing a conventional methodof checking a connector for continuity.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiments of this invention will now be described with reference tothe attached drawings.

Referring to FIG. 1, a compressor or compressed air constituting apressure source 21 is connected through an air pipeway 28 to a regulator22 to be regulated at a predetermined pressure, e.g. 5.0 kg/cm². Theregulator 22 is connected to an ejector (a changing valve for changing apressure from positive to negative) 23 to depressurize to apredetermined pressure. A waterproofness checking jig 24 and a pressuresensor 25 are connected in a branched manner to the ejector 23, on whichwaterproofness checking jig 24 is set a waterproof connector A in awatertight manner as later described. The pressure sensor 25 has afunction of detecting and displaying the pressure in the waterproofconnector A set on the waterproofness checking jig 24 as well as afunction of comparing the detected pressure with a preset referencepressure to judge whether the waterproof connector A is good anddisplaying the result of the judgement. The result of the judgement isindicated, for example, on a display 19 or by a buzzer.

Designated at 28 is a power source with a switch 27. If the switch 27 isturned on, the ejector 23 is operated to depressurize the waterproofnesschecking jig 24, and the pressure therein is displayed and judged by thepressure sensor 25.

FIG. 2 is a perspective view of an apparatus B for checking thewaterproofness of a waterproof connector A, which implements the systemblock diagram in FIG. 1. In this figure, like parts or elements as inFIG. 1 are denoted by like reference characters.

Designated at 29 in FIG. 2 is a base plate of lightweight material suchas synthetic-resin, aluminum or the like. At the front half of the baseplate 29, a waterproofness checking jig 24 is arranged on one side (leftside in the figure), a pressure sensor 25 on the other side, and aswitch 27 at an intermediate position therebetween. At the rear half ofthe base plate 29, i.e., in back of the switch 27 and the pressuresensor 25, there are respectively arranged an ejector 23 and a powersource 26. An air pipeway 28 on the depressurization side of the ejector23 is branched through a coupling 30 to be connected to thewaterproofness checking jig 24 and to the pressure sensor 25. With theaid of a not-shown electric wiring on the underside of the base plate29, if the switch 27 is turned on, a change valve (not-shown) in theejector 23 is operated to depressurize the waterproofness checking jig24. The reduced pressure in the jig 24 is transmitted to the pressuresensor 25 to be indicated and further to be compared with the referencepressure. The change valve also serves to keep the interior of thechecking jig 24 in the depressurized state, though any other means isemployable so long as capable of performing the same function.

Referring to FIGS. 3 and 4, the waterproofness checking jig 24 comprisesa framing 31, a sub-holding block 32 provided at one end thereof, aslidable connector-holding block 34 in opposition to the block 32, and alever 38 with a toggle mechanism which moves the connector-holding block34 forwardly and backwardly.

The framing 31 is trough-shaped and comprises a bottom plate 31a andlateral plates 31b on opposite sides of the bottom plate 31a. Eachlateral plate 31b is at the front end portion formed with a notch 31c'and above the notch 31c' formed with an upwardly-extended connectorsupport plate 31c. The sub-holding block 32 is interposed between theopposite connector support plates 31c.

The sub-holding block 32 is for supporting the terminal insertion sideof the waterproof connector A, i.e., the side from which terminals areinserted. The subholding block 32 is provided in a depressed shapeopened forwardly and rearwardly as well as upwardly, and has an innerstep 32a complamentary to an external shape of the connector housing tobe held (housing body 1, waterproofing hood 6 in FIG. 8 or the like).The sub-holding block 32 between the connector support plates 31c, 31cis securely screwed to the framing 31 along with a depressed keep plate33.

The connector-holding block 34 is for holding in a watertight manner thefitting side of the waterproof connector A with a mating connector andhas at the front a recessed portion 34a for receiving the fitting sideof the connector A, in which recessed portion is provided an elasticpacking 35 for close contact with the fitting surface of the waterproofconnector A (the end surface 1a of the housing body 1 in FIG. 8) and towhich recessed portion is connected to the pipeway 28 on thedepressurization side as mentioned above.

The connector-holding block 34 is provided slidable between thesub-holding block 32 and the other end of the framing 31. For thispurpose, the connector-holding block 34 is at a lower portion thereofprovided with a pair of guide holes 34b, and guide rods 36 which extendthrough the guide holes 34b are at one end fixed to the sub-holdingblock 32 and at the other end fixed to a rod stopper 37 provided at thebottom plate 31a of the framing 31.

The lever 38 comprises a pair of opposed lever plates 39, 39 connectedto each other to form a gate-like shape. Each lever plate 39 comprisesan upright base portion 39a of large width and an operating portion 39bobliquely upwardly extending from the base portion 39a as an integralpart thereof. The lever plates 39, 39 are at the upper end and anintermediate portion, i.e., at both ends of their operating portions 39bconnected to each other by means of a spacer 40 and a joint rod 41.

The upright base portions 39a are at the lower, rear end thereofrotatably connected through a pin 42 to tabs 31d provided at the rearend of the lateral plates 31b of the framing 31. Links 43 are at one endconnected through pins 44 to the lower, front end of the upright baseportions 39a and at the other end connected through stud bushes 45 toside walls of the connector-holding block 34.

A toggle mechanism is employed for the lever 38, the links 43 and theconnector-holding block 34, in which the pins 44 are slightly loweredfrom the position whereat the pins 44 are aligned with the pin 42 andstud bushes 45 so that the waterproof connector A is held and locked ina watertight manner between the sub-holding block 32 and theconnector-holding block 34.

The method of checking the waterproofness of the waterproof connector Awith the waterproofness checking apparatus B having the waterproofnesschecking jig 24 will now be described.

First, referring to FIG. 3, the lever 38 is rotated upwardly asindicated by an arrow P to part the connector-holding block 34 from thesub-holding block 32.

The terminal-insertion side of the waterproof connector A is then fittedin the sub-holding block 32 from above. Thereafter, the lever 38 isrotated in the direction opposite to the arrow P to cause theconnector-holding block 34 to approach the sub-holding block 32 so thatthe fitting side of the waterproof connector A enters the recessedportion 34a to bring its fitting surface 1a into close contact with theelastic packing 35. If the lever 38 is further rotated downwardly untilthe pins 44 are located slightly below the center line passing throughthe pin 42 and the stud bush 45, the lever 38 is locked due to thetoggle mechanism mentioned above; The waterproof connector A is thusheld in a watertight manner by the waterproofness checking jig 24.

After the waterproof connector A has thus been set on the waterproofnesschecking jig 24, the switch 27 in FIG. 2 is turned on to operate theejector 23 and depressurize the inside of the waterproof connector A.

As soon as the depressurization is started, the pressure sensor 25displays the value of the pressure inside the waterproof connector A,which becomes definite in a short period of time.

In other words, if the waterproof connector A is free of leakage, thepressure coincides with the reference pressure stored in advance in thepressure sensor 25. If there is leakage, or if there is, for example, apinhole in the housing body 1 or the waterproofing rubber stopper 5, thepressure inside the waterproof connector A does not reach apredetermined reduced pressure, and the buzzer is sounded indicatingfaulty on comparison with the reference pressure.

Thus, the setting of the waterproof connector A on the waterproofnesschecking jig 24 and its checking for waterproofness can be very easilyand quickly done.

Further, since the inside of the waterproof connector A is depressurizedby the ejector 23, there is no fear that the waterproofing rubberstopper 5 may pop out. Rather, if the rubber stopper 5 is insertedincomplete, it is pulled deeper inside the connector housing by thedepressurization attraction to be fully inserted.

Further, if necessary, by so arranging that the waterproof connector Amay be pressurized by operating the switch 27 and closing (or opening)the change valve of the ejector 23, it becomes possible to check forwaterproofness based on a positive pressure.

FIG. 5 shows a structure in which the depressurization of awaterproofness checking apparatus is used to prevent incompleteinsertion of a female terminal 51 into a waterproof connector A'.

The waterpoofness checking apparatus 52 includes a connector-holdingblock 54 with a fitting room 53 into which the waterproof connector A'is fitted. The connector-holding block 54, as described in connectionwith FIG. 3, is a part of a waterproofness checking jig, and a viewshowing the entire checking jig is omitted. The connector-holding block54 is formed with a plurality of conductive-pin receiving holes 55 and asuction hole 58, all of which extend parallel to each other and areconnected to the fitting room 53. A smaller diameter portion 57 isextended from the end of each conductive pin receiving hole 55, intowhich smaller diameter portion is inserted and fixed a terminal pin 58.Each conductive pin 59 is at the rear end provided with a flange portion60 for abutment against a stopper 61 provided at an intermediate portionof the related conductive pin receiving hole 55.

The terminal pin 58 is capable of advancing into the conductive pin 59,and a coil spring 62 is provided between the flange portion 80 of theconductive pin 59 and the end of the receiving hole 55 to urge theconductive pin 59 towards the fitting room 53. The front half of theconductive pin 59 projects into the fitting room 53 to bring its frontend 59a into contact with the front end 51a of the female terminal 51fully inserted into the waterproof connector A'. The suction hole 56opens at the front end to the fitting room 53 and at the rear endconnected to an external pipeway 63 through welding or the like, whichexternal pipeway is in turn connected to a depressurizing compressor 64.

Into the fitting room 53 is engaged the housing body 65 of thewaterproof connector A' which contains therein female terminals 51. Inthe state in FIG. 5, the housing body 65 is fully inserted into apredetermined position in the fitting room 53. A waterproofing elasticpacking 68 is fitted around the housing body 85 at the proximal sidethereof with a lip portion closely contacting the inner surface 67 atthe front end of the fitting room 83. An insulated wire 69 is attachedto the female terminal 51 accommodated in the terminal accommodatingchamber (terminal accommodating hole) in the housing body 65. Theinsulated wire 89 has a waterproofing rubber stopper 70 fitted thereoverwhich closely contacts the inner surface of a larger-diameter portion atthe rear portion of the terminal accommodating chamber 68. A crimp piece71 of the female terminal 51 is crimped to hold the waterproofing rubberstopper 70 and the wire 89 together as an integral unit. The inside ofthe fitting room 53 is maintained watertight by means of the elasticpacking 66 and the waterproofing rubber stopper 70.

If the waterproof connector A' is fully engaged in the fitting room 53as shown in FIG. 5 (no further insertion of the connector A' into thefitting room 53 is possible), an air gap 53a of some size is formedbetween the front end of the connector A' and the bottom wall of thefitting room 53, through which air gap and through the suction hole 56the terminal-accommodating chambers 68 in the connector A' aresimultaneously depressurized. A lead wire 72 is connected on one hand tothe insulated wire 69 of the termial 51 and on the other to the termialpin 58, and has a power source 73 and a check lamp 74 connected atintermediate positions thereof. Each female terminal 51 is locked inposition in the terminal accommodating chamber 88 by a resilient lockinglance 75 provided in the housing body 67.

If in this instance the female terminal 51 is inserted incomplete, sincethe advancement of the conductive pin 59 is limited by the stopper 81,the tip end 59a of the conductive pin 59 does not come into contact withthe front end 51a of the female terminal 51, and faulty continuity isdetected. On the other hand, during the depressurization of the fittingroom 53 and the connector A' for checking the waterproofness of theconnector, which is effected by the compressor 64 through the suctionhole 56, the waterproofing rubber stopper 70 and thus the femaleterminal 51 are pulled forwardly (deeper in the female terminalinsertion direction) to bring the terminal 51 into its fully-insertedposition. Owing to the above, the terminal inserted incomplete iscorrected to be fully inserted, with the result that the female terminal51 and the conductive pin 59 are brought into contact with each other toprovide good continuity, and that the slipping-off of anincompletely-inserted terminal is prevented.

Incidentally, the stopper 61 may be omitted in FIG. 5. In this case,continuity is made between the female terminal 51 and the conductive pin59 even if the former is inserted incomplete, and good conductivity willbe displayed. An incompletely-inserted terminal is sucked into itsfully-inserted position no matter what the display may be. Further, astructure may be employed in which, with the stopper 61 maintained as itis, a gap is formed between the rear end 60 of the conductive pin 59 andthe front end of the terminal pin 58, and the tip end 59a of theconductive pin 59 is contactable with the female terminal 51 when thelatter is inserted so that the full insertion of the female terminal 51brings the conductive pin 59 into contact with the terminal pin 58.Alternatively, a stopper may be provided towards the front end of theconductive pin 59 so as to abut against the front end of the connectorhousing 65.

FIGS. 6 and 7 show the state in which the female terminal 51 is lockedin position in the waterproof connector A' by the resilient lockinglance 75 of the connector housing 65. In this embodiment, to avoid thesituation in which the engagement hole 78 in the base plate 77 of thefemale terminal 51 stops just in front of the engagement projection 76of the resilient locking lance 75 to remain unengaged with the latter,the positioning of the connector A in the waterproofness checking jig issuch that at the initial stage of full insertion of the terminal inwhich the front end 76a of the engagement projection 76 abuts againstthe front end 78a of the engagement hole 78 as shown in FIG. 6, thefront end 51a of the female terminal 51 does not contact the front end59a of the conductive pin 59. In other words, the distance L1 betweenthe front end 59a of the conductive pin 59 and the front end 76a of theengagement projection 76 is set larger than the distance L2 between thefront end 51a of the female terminal 51 and the front end 78a of theengagement hole 78, and the length of the engagement hole 78 is setlarger than the length of the engagement projection 76.

With the construction as mentioned above, when the connector A' isdepressurized for the checking for waterproofness, the female terminal51, along with the waterproofing rubber stopper 70, is attracted andmoved in the terminal insertion direction by the distance correspondingto the longitudinal play between the engagement hole 78 and theengagement projection 76. With the rear end (sloping portion) 76b of theengagement projection 76 abutting against the rear end 78b of theengagement hole 78, the front end 51a of the female terminal 51 contactsthe front end 59a of the conductive pin 59, and good continuity isindicated.

By the suction operation of the compressor 64, the female terminal 51 iscapable of moving forwardly along the rear end (sloping portion) 76b ofthe engagement projection 76 until the front end 51a of the femaleterminal 51 abuts against a stop wall 79 at the front end of theterminal-accommodating chamber 68 in the housing body 65, at which timethe front end 51a of the female terminal 51 contacts the conductive pin59 without fail, and the engagement projection 78 engages in theengagement hole 78. Owing to the above, if there are variations inlongitudinal sizes of locking projections 78 and engagement holes 78, itis prevented that the engagement projection 76 stops just in front ofthe engagement hole 78 to remain unengaged with the latter, whileenabling detection of continuity.

What is claimed is:
 1. A method of checking a waterproof connector for waterproofness comprising a connector housing with a terminal-accommodating chamber formed therein into which a terminal attached to an end of an insulated wire has been inserted from a first side of said connector housing, said terminal-accommodating chamber having been sealed by a waterproofing rubber stopper through which said insulated wire passes, said method comprising the steps of:engaging a connector-holding block in a watertight manner with a second side of said connector housing at which said connector is fitted with a mating connector; depressurizing an interior of said connector through said connector-holding block; and detecting and comparing a pressure inside said connector with a reference pressure preset to determine presence or non-presence of leakage.
 2. An apparatus for checking a waterproof connector for waterproofness, comprising:a waterproofness checking jig provided with a connector-holding block for engaging and holding in a watertight manner a fitting side of said connector with a mating connector; means for depressurizing an interior of said connector through said connector-holding block and means for holding the interior of said connector in the depressurized state; means for detecting a pressure inside said connector a certain period of time after commencement of holding in the depressurized state and comparing the same with a reference pressure preset to determine presence or non-presence of leakage; and means for displaying said detected pressure inside said connector and the presence or non-presence of leakage. 